Suddenly when he reached very high rotation speeds, the ball magnet exploded, probably due to centrifugal forces and several of the neodymium parts have penetrated and ripped through his right hand !!

So please be very careful with rapidly rotating sphere magnets!

If there are high centrifugal forces at play the ball magnets can fall apart and then the shattered parts fly off like bullets!

But he had probably tried too extreme speeds so far stated from his friends, beyond the 100.000 revolutions per minute range!

Then, if the ball magnet inside already had a small fracture or an had internal crack due to falling to the ground once, then it may be due to the extreme centrifugal forces that such a bad accident can happen… !

These ball magnets are also only produced by pressing together the neodymium powder, so they will not withstand too much centrifugal forces !

R. was already operated 2 times in hospital !

He was lucky to get nothing into his face or the head thank God! , but parts of the magnet stuck 2 cm into the wall of his room !

It was just about 1 inch diameter large neodymium ball magnet , which was torn apart by the centrifugal forces
at these high rotation speeds !

Here are some hints and safety considerations of the VisionBlue Energy Team:

Coat the magnet in an epoxy if possible to prevent the shattering from branching out as far or even carbon fiber wrap to prevent it from going off like a grenade.

Mark Euthanasius

Machinery deserves respect. One should assume that any element of a set-up can fail without warning. People should follow the example of those like Russ Gries who make good safety practices a matter of routine.

MagnaMoRo

It is not that the magnet broke apart due to “centrifugal forces”… The correct way to state this is that very high speed centrifugal (rotational) ‘activity’ caused stress on the bonds between molecules making up the magnet, to the point where it broke apart due to insufficient molecular bonding forces (centripetal forces).

For example, the moon remains at its set distance only because the centrifugal activity (rotational speed) balances the gravitation attraction forces (centripetal forces).

Asterix

Well, those neodymium magnets are pretty brittle. Not the sort of thing that you want to subject naked to high mechanical stress. I’ve dropped a large one on a hard surface only to have it fracture.

Gramps.

used to be in a machine shop was a precision grinder working to very close tolerances.. Anytime we exeeded 100k Rpm wheel and bearings were alwys sheilded with a steel guard. Those kind of Rpms create tremendious centrifical forces. All you have to do is have anything slightly out of balance and it will self destruct. ‘